Hypertension is one of the most important independent risk factors for chronic kidney disease (CKD) progression. The results of the recently completed ESCAPE trial highlight the importance of blood pressure control as a means to slow CKD progression, making antihypertensive nonadherence a prime target for behavioral intervention. Surprisingly, there is no research on adherence to antihypertensive medication among children either with or without CKD. Physician-adolescent communication is key for facilitating lifelong self-management skills and changes as the adolescent matures and assumes more responsibility for his/her care. However, there is a striking gap in our knowledge of physician-adolescent communication in general and specifically how it impacts regimen adherence and health outcomes. Evaluating how known risk and resilience factors and physician-adolescent communication interact through a comprehensive, longitudinal predictive model of adolescent nonadherence in CKD is an essential prelude to the development of effective, targeted adherence interventions for high-risk patients. The purpose of this study is to test 1) the impact of antihypertensive medication adherence in adolescents on blood pressure control and subsequent progression of CKD; and 2) the influence of physician-adolescent communication on medication adherence over time. This is a prospective study of 150 adolescents age 11-19 years old with CKD (Stages 1-5) who are prescribed an antihypertensive medication. Objective measurement approaches will be used to assess antihypertensive medication adherence (electronic monitoring and pharmacy refills), health outcomes (e.g., ambulatory blood pressure monitoring and biomarkers of CKD progression), and physician-adolescent communication (RIAS coding of nephrology clinic visits). Additionally, the moderating effect of known nonadherence risk and resilience factors on the association between physician-adolescent communication and adherence will be assessed. All variables will be measured at baseline, 12- and 24- months; additionally, adherence and health outcomes will be measured at 6-, 18- and 30-months. Longitudinal analyses will be used to model the change in outcomes with time-varying covariates. This will allow us to evaluate how changes in physician-adolescent communication impact adherence and then subsequent blood pressure control and CKD progression. Further, the lessons learned in this study of adolescents with CKD will add to our understanding of the impact of physician-adolescent communication across chronic illnesses.